Asclepias curassavica

Typical plants are evergreen perennial subshrubs that grow up to 1 m (3.3 ft) tall and have pale gray stems. The leaves are arranged oppositely on the stems and are lanceolate or oblong-lanceolate shaped ending in acuminate or acute tips. Like other members of the genus, the sap is milky. The flowers are in cymes with 10-20 flowers each. They have purple or red corollas and corona lobes that are yellow or orange. Flowering occurs nearly year-round.[5] The 5–10 cm (2.0–3.9 in) long, fusiform shaped fruits are called follicles. The follicles contain tan to brown seeds that are ovate in shape and 6–7 mm (0.24–0.28 in) long. The flat seeds have silky hairs that allow the seeds to float on air currents when the pod-like follicles dehisce (split open).[12]

There are a number of different cultivars with improved flower colors and shorter habit; some have bright red, yellow or orange colored flowers. Asclepias curassavica is sometimes used in butterfly gardens (see above for concerns for monarchs) or as a cut flower. However, when the stems or leaves are broken, a poisonous milky sap exudes which can cause eye injury.[13]

Asclepias curassavica is described by NatureServe as a "widespread species, ranging from southern North America through Central America and into South America."[1]

It is an introduced species in the US states of California, Florida, Hawaii, Louisiana, Tennessee, and Texas, as well as the US unincorporated territories of Puerto Rico and the United States Virgin Islands.[14]

It has been introduced and naturalized in the Chinese provinces of Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangsu, Jiangxi, Qinghai, Sichuan, Xizang, Yunnan, and Zhejiang, as well as in Taiwan.[5]

Asclepias curassavica was introduced to Australia prior to 1869 and is widespread in parts of Queensland.[15] It is considered an exotic plant, and a weed, at the Meteor Downs South Project near Rolleston, Queensland, Australia.[16]

Asclepias curassavica contains several cardiac glycosides,[17] including asclepin,[18] calotropin, uzarin and their free genins, calactin, coroglucigenin and uzarigenin.[19] It also contains oleanolic acid, β-sitosterol, and glycosides of asclepin. The most abundant cardiac glycoside present in Asclepias curassavica leaves is voruscharin, which comprises around 40% of the total cardiac glycoside content in leaves.[20]

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  Flower from flower biew
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  Fruits
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  Seeds
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  Seed with parachute
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  Seeds close up
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  Flower closeup
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  Flowers with ants feeding on the nectar
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  Monarch caterpillars feeding on milkweed.
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  Asclepias curassavica 'Silky Gold'
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  Scarlet milkweed with a Monarch caterpillar and large milkweed bugs

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Wikispecies has information related to Asclepias curassavica.

• Jepson Manual (1993)—description of introduced species and non-native California distribution